By this spring, all national universities in the nation had created export control sections to prevent nuclear, radar and other high-level technologies with the potential for military use from being transferred abroad, and had set relevant rules, according to the education ministry.

Last year, five of the 86 state-run universities did not have such units and 17 had lacked rules on export controls. But as of April, all of the institutions had introduced both, a tally by the Education, Culture, Sports, Science and Technology Ministry showed.

Universities in Japan have faced growing calls to tighten their export controls and the United States, which has raised questions about China stealing technology, has called on its allies to take such steps.

There have been fears that any delay in boosting export control measures could result in Japanese universities being excluded from joint research opportunities with peers from the United States and other countries.

Guidelines drawn up by the Ministry of Economy, Trade and Industry, which oversees issues related to export controls, urge domestic universities to assign personnel to be responsible for determining whether each technology should be subject to export restrictions based on the nation’s foreign exchange and foreign trade law.

Universities are supposed to ensure their technologies are not transferred overseas by using checklists to decide whether to accept international students and researchers, as well as whether to allow them to transfer their research results and other materials, according to the guidelines.

A separate education ministry survey also found that 213 universities in the nation that have science courses and are run by local governments or private bodies — around 60 percent of the total — have taken export control measures.

But the Japanese institutions are facing a dilemma. Against a backdrop of a dwindling number of Japanese students in the fields of science and engineering, they have started to rely significantly on students and researchers from abroad, including many Chinese nationals, in the fields of artificial intelligence and other high-tech research.

At the University of Tokyo, Chinese accounted for about 60 percent of some 4,000 foreign students on its undergraduate and graduate courses as of May, according to the university.

A trade ministry report said a foreign student was caught attempting to transfer a technology that is subject to export controls without permission, while another student was found to have belonged to an organization suspected of having engaged in developing weapons of mass destruction back home.

Mikihito Kano, an associate professor versed in intellectual property at Mie University, hailed the moves by universities to establish export control units and set rules, as it is difficult for individual researchers to judge whether their studies and technologies are subject to export restrictions.

“But it is usually unclear at the research stage whether a certain technology could be used for military purposes,” Kano said, adding that excessive export controls would undermine active research.